Why did george mendel choose to use purebred plants in his experiments

Of the pollutants that form acids in the atmosphere, which is easiest to reduce? a. sulfur dioxide b. nitrogen dioxide c. ozone d. carbon monoxide

Aboy with an extra x chromosome probably has which of the following syndromes?

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.